My GLE350 is 18 months old and I was using cruise control for an extended period of time over the past couple of weeks. Looking for advice on a couple of things:

1) the default setting for the speed limit sign recognition is downright dangerous. I would be cruising along and it would simply lower my speed according to the speed limit sign, in the middle of an interstate with traffic all around. It cannot determine the difference between a minimum and maximum speed limit sign, so I'd be going along at around the limit, would pass a 40 mph minimum sign and the car would slam on the brakes. Fortunately I was able to figure out how to turn that off. But there's more ..

2) even with the sign detection turned off, I had several scary moments in the dark where the system simply decided that the limit was 65 mph at night. A message would appear informing me of that as the car hit the brakes. How can this be disabled, it is incredibly dangerous?

3) and how can you disable the system from deciding to randomly slow down because there is a curve in the road coming up?

These issues made it very tiring to drive the car since you have no idea what random behavior it was going to exhibit next.

Do you have Distronic or do you really just have cruise control? It sounds like you are describing Distronic.
I had the problem you describe using Distronic, part of the Driver Assistance Package. Here are some suggestions:

1. Have your Dealer check your car for Outgassing, a known issue. The camera housing plastic gives off fumes that cloud the lens making it difficult for the camera to read traffic signs correctly…worse on cloudy days or evening. On mine this fix eliminated most of the sign misreads. Have your Dealer check-Tech Topics, October 2021.

2. Check to see if your set speed is reduced to the incorrect speed limit reading. If it is then a quick workaround on mine was to tap the accelerator pedal quickly and the set speed changed back to the prior setting. This is a bandaide but an easy way to get back to normal.

3. Make sure you have the option to avoid the car from braking aggressively turned off-The Limit Adoption option in the Traffic Sign Assist menu is a selection located below the option to turn off traffic signs, scroll down, turn off limit adoption. (Thanks to @Djer for this info)

Although annoying, I have become accustomed to it. Just a quick tap on the gas pedal and your right back to where you want to be, and barely noticeable to the driver behind you. On the flip side, it also increases speed automatically when it reads a higher posted limit - I like this part!!! Good for avoiding speed traps.

Yes, it is Distronic. I'm taking it to the dealer soon and will have them check all of this out. It's very frustrating to use. I finally figured out the Limit Adoption and I turned everything off in the traffic sign assist. But I still got the random slow down in the middle of the night.

Inaddition to turning off limit adoption, also turn off route based speed. Route based speed slows the car down for curves and traffic jams and toll booths as reported by HERE. Real annoying when the traffic jam has cleared yet the car brakes as if it is still there, and it brakes for a toll booth when you have a fast pass transponder. Also, distronic will brake when going down hill to maintain the set speed.

So much for "driver assistance" systems. That's why I didn't order the nannies.